1 files changed, 32 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
index 5c175519cf9e..85bb66d7f933 100644
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -35,6 +35,8 @@
 #include "powernv.h"
 #include "pci.h"
 
+/* Delay in usec */
+#define PCI_RESET_DELAY_US      3000000
 
 #define cfg_dbg(fmt...) do { } while(0)
 //#define cfg_dbg(fmt...)       printk(fmt)
@@ -354,6 +356,35 @@ static void __devinit pnv_pci_dma_dev_setup(struct pci_dev *pdev)
                 pnv_pci_dma_fallback_setup(hose, pdev);
 }
 
+static int pnv_pci_probe_mode(struct pci_bus *bus)
+{
+        struct pci_controller *hose = pci_bus_to_host(bus);
+        const __be64 *tstamp;
+        u64 now, target;
+
+
+        /* We hijack this as a way to ensure we have waited long
+         * enough since the reset was lifted on the PCI bus
+         */
+        if (bus != hose->bus)
+                return PCI_PROBE_NORMAL;
+        tstamp = of_get_property(hose->dn, "reset-clear-timestamp", NULL);
+        if (!tstamp || !*tstamp)
+                return PCI_PROBE_NORMAL;
+
+        now = mftb() / tb_ticks_per_usec;
+        target = (be64_to_cpup(tstamp) / tb_ticks_per_usec)
+                + PCI_RESET_DELAY_US;
+
+        pr_devel("pci %04d: Reset target: 0x%llx now: 0x%llx\n",
+                 hose->global_number, target, now);
+
+        if (now < target)
+                msleep((target - now + 999) / 1000);
+
+        return PCI_PROBE_NORMAL;
+}
+
 void __init pnv_pci_init(void)
 {
         struct device_node *np;
@@ -384,6 +415,7 @@ void __init pnv_pci_init(void)
         ppc_md.pci_dma_dev_setup = pnv_pci_dma_dev_setup;
         ppc_md.tce_build = pnv_tce_build;
         ppc_md.tce_free = pnv_tce_free;
+        ppc_md.pci_probe_mode = pnv_pci_probe_mode;
         set_pci_dma_ops(&dma_iommu_ops);
 
         /* Configure MSIs */